People in the rich world should become "demitarians" – eating half as much meat as usual, while stopping short of giving it up – in order to avoid severe environmental damage, scientists have urged, in the clearest picture yet of how farming practices are destroying the natural world.

They said the horsemeat scandal had uncovered the dark side of our lust for meat, which has fuelled a trade in undocumented livestock and mislabelled cheap ready meals. "There is a food chain risk," said Prof Mark Sutton, who coined the term demitarian and is lead author of a UN Environment Programme (Unep) study published on Monday. "Now is a good time to talk to people about this.".